A need exists to develop a smaller, lighter, more efficient and more reliable clinical gas analyzer for respiratory and anesthetic gas monitoring. Existing laser Raman based instrumentation uses a large, heavy and extremely inefficient (0.1 %) argon ion laser with an intracavity gas cell which is subject to contamination and misalignment. The long term objective is to implement a solid state laser alternative to the existing laser and an external cavity gas cell which is much less susceptible to contamination. Such a laser is smaller, lighter, much more efficient and has lifetimes greatly exceeding hose of the present laser. The specific aims are: (1) build a single channel prototype utilizing the solid state laser, an extracavity gas cell, selected specific dielectric interference filters for rejection of the elastic scattered laser light and transmission of gas specific Raman line, and solid state photodetectors. (2) evaluate the prototype or accuracy, linearity, sensitivity, precision, stability and interference between various anesthetic and respiratory gases,(3) compare the maximum signals for pure gases to those calculated on the basis of a system modelling equation.